<meta charset="UTF-8" />

<div class="box">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>

<style>
  body {
    margin: 0px;
  }

  .box {
    display: flex;
    flex-wrap: wrap;
    margin-left: -20px;
    margin-top: -20px;

    padding: 20px;
  }

  .item {
    display: inline-block;
    height: 150px;
    width: calc(50% - 20px);
    margin-top: 20px;
    margin-left: 20px;
    background-color: brown;
    border-radius: 8px;
  }
</style>
